Spring-Assisted Surgery of Unilambdoid Craniosynostosis.

Craniosynostosis is traditionally treated with extensive cranial vault reconstructions (CVRs). Although less invasive techniques, such as endoscopic strip craniectomy with postoperative helmet therapy, have been successful, they also present difficulties. An alternative method is distraction osteogenesis using either manually controlled devices or specially designed springs. In this study, the authors provide the first comparison of spring-assisted surgery (SAS) with CVR for the treatment of unilambdoid synostosis (ULS). Fourteen consecutive patients (8 CVR and 6 SAS) treated for ULS at Sahlgrenska University Hospital between 2005 and 2018 were included. Skull shape and deviations were evaluated using previously defined measurement points on 3-dimensional computed tomography scans preoperatively, at spring removal, and at 3 years of age. Posterior and middle cranial fossa (PCF and MCF, respectively), skull-base cant, facial twist, and mastoid bulge (MB) were measured, and clinical data were obtained from chart reviews. The results indicated that at the 3-year follow-up, PCF, MCF, and MB improved in both groups, with no significant difference in outcome observed between methods. In the SAS group, duration of operation [61±27 min (mean±SD)] and perioperative bleeding (3.5±2.8 mL/kg body weight) were both significantly lower relative to the CVR group (P<0.05). These findings showed that both SAS and CVR resulted in similar improvements in treating ULS, although neither produced complete normalization of skull shape. The results suggest that early diagnosis and operation allow less extensive SAS to be performed without adversely affecting the results.

Improved Facial and Skull-Base Symmetry following Osteotomy and Distraction of Unilateral Coronal Synostosis.

BACKGROUND: Unilateral coronal synostosis (UCS) results in a surgically demanding deformation, as the deformity is asymmetric in the calvaria but also presents with facial scoliosis and orbital dystopia. Traditional cranioplasties correct the forehead but have little effect on the face and orbits. In this article, the authors describe a consecutive series of patients operated on for UCS with osteotomy of the fused suture combined with distraction osteogenesis. METHODS: Fourteen patients (mean age, 8.0 months; range, 4.3 to 16.6 months) were included in this study. The authors measured and compared the orbital dystopia angle, anterior cranial fossa deviation, and anterior cranial fossa cant between preoperative computed tomography results and those at distractor removal. RESULTS: Blood loss was 6.1 mL/kg (range, 2.0 to 15.2 mL/kg), and length of stay was 4.4 days (range, 3.0 to 6.0 days). The authors observed significant improvements in the median orbital dystopia angle from 9.8 degrees (95% CI, 7.0 to 12.6 degrees) to 1.1 degrees (95% CI, -1.5 to 3.7 degrees) ( P < 0.001), anterior cranial fossa deviation from 12.9 degrees (95% CI, 9.2 to 16.6 degrees) to 4.7 degrees (95% CI, 1.5 to 7.9 degrees) ( P < 0.001), and anterior cranial fossa cant from 2.5 degrees (95% CI, 1.5 to 3.5 degrees) to 1.7 degrees (95% CI, 0.0 to 3.4 degrees) ( P = 0.003). CONCLUSIONS: Osteotomy combined with a distractor for UCS straightened the face and relieved orbital dystopia by affecting the nose angle relative to the orbits, correcting the deviation of the cranial base in the anterior fossa, and lowering the orbit on the affected side. Furthermore, this technique demonstrated a favorable morbidity profile with low perioperative bleeding and a short inpatient period, suggesting its potential to improve the surgical treatment of UCS. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Correction of Unicoronal Synostosis With Springs: Two Patients With Improved Facial Symmetry.

OBJECTIVE: Surgical correction of unicoronal synostosis (UCS) entails extensive cranioplasties which do not address facial scoliosis. This paper presents the first results with springs that motivated the shift from extensive cranioplasties to dynamic techniques for surgical correction of UCS. METHODS: Two cases of UCS were operated with a linear osteotomy combined with springs. The deviation in facial symmetry (orbital dystopia angle) and skull base angles were measured on pre and postoperative computed tomography scans until 3 years of age. RESULTS: The facial scoliosis was corrected. At spring removal, the orbital dystopia angle had gone from a 9.2 to 13.2-degree deviation preoperatively to a 0.5 to 0.9-degree overcorrection compared with the ideal 0-degree deviation. Also, the skull base deviation improved. CONCLUSION: Linear osteotomy combined with springs corrects the facial scoliosis in UCS. These cases indicate that dynamic methods may be beneficial for improving the results of surgical correction of UCS.

Springs Produce Favorable Morphological Outcomes Relative to H-craniectomy According to a Two-center Comparison of Matched Cases.

BACKGROUND: Sagittal synostosis is the most common type of premature suture closure, and many surgical techniques are used to correct scaphocephalic skull shape. Given the rarity of direct comparisons of different surgical techniques for correcting craniosynostosis, this study compared outcomes of craniotomy combined with springs and H-craniectomy for non-syndromic sagittal synostosis. METHODS: Comparisons were performed using available pre- and postoperative imaging and follow-up data from the two craniofacial national referral centers in Sweden, which perform two different surgical techniques: craniotomy combined with springs (Gothenburg) and H-craniectomy (Renier's technique; Uppsala). The study included 23 pairs of patients matched for sex, preoperative cephalic index (CI), and age. CI, total intracranial volume (ICV), and partial ICV were measured before surgery and at 3 years of age, with volume measurements compared against those of pre- and postoperative controls. Perioperative data included operation time, blood loss, volume of transfused blood, and length of hospital stay. RESULTS: Craniotomy combined with springs resulted in less bleeding and lower transfusion rates than H-craniectomy. Although the spring technique requires two operations, the mean total operation time was similar for both methods. Of the three complications that occurred in the group treated with springs, two were spring-related. Importantly, the compiled analysis of changes in CI and partial volume distribution revealed that craniotomy combined with springs resulted in superior morphological correction. CONCLUSIONS: The findings showed that craniotomy combined with springs normalized cranial morphology to a greater extent than H-craniectomy based on changes in CI and total and partial ICVs over time.

Circulating Brain-Injury Markers After Surgery for Craniosynostosis.

OBJECTIVE: Historically, there have been few quantitative methods for effectively evaluating outcomes after surgery for craniosynostosis. In this prospective study, we assessed a novel approach for detecting possible postsurgery brain injury in patients with craniosynostosis. METHODS: We included consecutive patients operated on for sagittal (pi-plasty or craniotomy combined with springs) or metopic (frontal remodeling) synostosis at the Craniofacial Unit at Sahlgrenska University Hospital, Gothenburg, Sweden, from January 2019 to September 2020. Plasma concentrations of the brain-injury biomarkers neurofilament light (NfL), glial fibrillary acidic protein (GFAP), and tau were measured immediately before induction of anesthesia, immediately before and after surgery, and on the first and the third postoperative days using single-molecule array assays. RESULTS: Of the 74 patients included, 44 underwent craniotomy combined with springs for sagittal synostosis, 10 underwent pi-plasty for sagittal synostosis, and 20 underwent frontal remodeling for metopic synostosis. Compared with baseline, GFAP level showed a maximal significant increase at day 1 after frontal remodeling for metopic synostosis and pi-plasty (P = 0.0004 and P = 0.003, respectively). By contrast, craniotomy combined with springs for sagittal synostosis showed no increase in GFAP. For neurofilament light, we found a maximal significant increase at day 3 after surgery for all procedures, with significantly higher levels observed after frontal remodeling and pi-plasty compared with craniotomy combined with springs (P < 0.001). CONCLUSIONS: These represent the first results showing significantly increased plasma levels of brain-injury biomarkers after surgery for craniosynostosis. Furthermore, we found that more extensive cranial vault procedures resulted in higher levels of these biomarkers relative to less extensive procedures.

The value of genome-wide analysis in craniosynostosis.

Background: This study assessed the diagnostic yield of high-throughput sequencing methods in a cohort of craniosynostosis (CS) patients not presenting causal variants identified through previous targeted analysis. Methods: Whole-genome or whole-exome sequencing (WGS/WES) was performed in a cohort of 59 patients (from 57 families) assessed by retrospective phenotyping as having syndromic or nonsyndromic CS. Results: A syndromic form was identified in 51% of the unrelated cases. A genetic cause was identified in 38% of syndromic cases, with novel variants detected in FGFR2 (a rare Alu insertion), TWIST1, TCF12, KIAA0586, HDAC9, FOXP1, and NSD2. Additionally, we report two patients with rare recurrent variants in KAT6A and YY1 as well as two patients with structural genomic aberrations: one with a 22q13 duplication and one with a complex rearrangement involving chromosome 2 (2p25 duplication including SOX11 and deletion of 2q22). Moreover, we identified potentially relevant variants in 87% of the remaining families with no previously detected causal variants, including novel variants in ADAMTSL4, ASH1L, ATRX, C2CD3, CHD5, ERF, H4C5, IFT122, IFT140, KDM6B, KMT2D, LTBP1, MAP3K7, NOTCH2, NSD1, SOS1, SPRY1, POLR2A, PRRX1, RECQL4, TAB2, TAOK1, TET3, TGFBR1, TCF20, and ZBTB20. Conclusion: These results confirm WGS/WES as a powerful diagnostic tool capable of either targeted in silico or broad genomic analysis depending on phenotypic presentation (e.g., classical or unusual forms of syndromic CS).

In search of a single standardised system for reporting complications in craniofacial surgery: a comparison of three different classifications.

Comparing complication rates between centres is difficult due to the lack of unanimous criteria regarding what adverse events should be defined as complications and how these events should be compiled. This study analysed all adverse events in a cohort of craniofacial (CF) operations over a 10-year period and applied three different scales (Clavien-Dindo, Leeds and Oxford) for systematic comparison. A total of 1023 consecutive CF procedures in 641 patients was identified. The Clavien-Dindo scale captured 74 complications in 74 procedures (7.2%), whereas the Leeds and Oxford scales captured 163 complications in 134 procedures (13.1%) and 85 complications in 83 procedures (8.1%), respectively. The Clavien-Dindo scale appeared less suitable for CF surgery, because it is predominantly adapted to severe complications and also regards blood transfusion as a complication. The Leeds scale provided a detailed picture of all complications, as well as minor events, whereas the Oxford scale captured all major complications well but applied less accurate definitions for the minor events. Our findings contribute to the benchmarking of complications between CF centres and suggest that both the Leeds and the Oxford scale appear relevant, depending on the emphasis required for major and minor complications and inter-centre audits, respectively.

Temporal Deformity Objectively Measured Before and After Surgery for Metopic Synostosis: Retrusion Rather than Hollowing.

The temporal contour deformity typical of metopic synostosis is often referred to as temporal hollowing, but has not been quantitatively defined. This deformity is present before surgery and remains to a varying extent at long-term follow-up. The present study aimed to objectively evaluate the degree of this contour deformity in metopic synostosis before and after surgical correction.All children surgically treated for metopic synostosis at Sahlgrenska University Hospital between 2002 and 2014 (n = 120) with appropriate computed tomography scans (n = 160) performed preoperatively and/or at follow-up at 3 years of age were included. Depending on age, 1 of 2 surgical techniques was used. Children presenting before the age of 6 months were treated with frontal remodeling in combination with a spring (S group), whereas children older than 6 months were treated with a bone transplant (BT group). The bony temporal deformity was measured with a semiautomatic MATLAB program and patients were compared to sex- and age-matched controls.The deformity was significantly reduced in both groups (P < 0.001). In the S group, it was reduced from a mean ±â€Šstandard deviation of 3.6 ±â€Š1.9% to 1.0 ±â€Š1.2% and in the BT group, it was reduced from 3.3% ±â€Š1.4% to 1.1% ±â€Š0.8%.The contour deformity in metopic synostosis is present both before and after surgery and should therefore be termed temporal retrusion (TR). This assessment method enables objective comparison of TR before and after surgical correction and is a potential tool to evaluate TR in metopic synostosis.

The Degree of Surgical Frontal Volume Correction in Metopic Synostosis Determines Long-Term Outcomes.

Metopic synostosis results in a keel-shaped forehead, reduced frontal intracranial volume (ICV), and lower frontal to total volume ratio. The ratio improves with cranioplasty, but at 3 years of age, the ratio is still not normalized when compared to that in normal children. The aim of the present study was to investigate whether a low frontal to total ICV ratio at 3 years of age was due to relapse or insufficient correction.All children surgically treated for metopic synostosis in combination with a spring at Sahlgrenska University Hospital with subsequent spring extraction between 2002 and 2008 (n = 20) were included. A MATLAB program was used to measure frontal and total ICV.Preoperatively, the frontal to total ICV ratio was 9.8 ±â€Š1.3% (mean ±â€Šstandard deviation). At spring removal, 6 months after cranioplasty, the ratio had increased to 11.8 ±â€Š2.4%. At 3 years of age, the ratio was 11.6 ±â€Š1.9%. In age-matched normal children, the ratio was 14.4 ±â€Š1.9% preoperatively, 15.3 ±â€Š2.2% at time of spring extraction, and 13.4 ±â€Š1.4% at 3 years of age.Cranioplasty thus improved the frontal to total ICV ratio, but did not normalize it. The ratio did not change from 6 months after the cranioplasty to 3 years of age. These results indicate that a more pronounced frontal volume correction during cranioplasty is necessary to achieve a normalized distribution of ICV in metopic synostosis.